While you can’t see, touch, or smell it, bacteria play a major role in our world. These microscopic living organisms were among the first life forms to appear on Earth, and can be found on everything, from the bread you eat to the water you swim in. Bacteria can even live inside you, sometimes causing illnesses like strep throat and food poisoning. While bacteria are very simple single-celled microorganisms, they are essential to life as we know it. Some bacteria are “bad,” while other types of bacteria can have health benefits when consumed. Good bacteria, or probiotics, help keep the intestinal track in good working order and can offer numerous health benefits. Bacteria are a critical component to our lives and to the earth.

• Bacteria and Germs
• What are Bacteria?
• Why Should I Care About Germs?
• The Bad Bacteria

Bacteria are prokaryotic cells, meaning that they come in a variety of sizes and shapes. The three main shapes include rod like, spherical, and spiral. Most bacteria have the same basic structuring consisting of a cell wall which provides protection for the bacteria cell and a cell membrane which provides a tissue-like cushioning around the cell. Some bacteria cells have a nucleus (genetic material that floats in cytoplasm), while others have flagella, which allow the bacteria to move in its environment. Bacteria can form in the same way most living creatures are formed, through reproduction. Under the right conditions, bacteria can reproduce at great speeds, as much as once every 20 minutes. Bacteria reproduce using one of two methods: asexual reproduction or sexual reproduction. In asexual reproduction, only one parent is needed and the offspring are exact duplicates of the parent. If two parent cells exchange genetic material, this is sexual reproduction and the offspring will have a combination of the parent cells’ traits. Some types of bacteria are able to transfer pieces of their genes to other bacteria they come in contact with. This process, known as conjugation, allows one bacterium to connect to another through a protein tube called a pilus. The pilus is where the genes are transferred. Other bacteria can take DNA from their surroundings, mostly from dead bacterial cells. During a process called transformation, the bacterium binds with DNA and transports it across the cell membrane. New DNA is then combined with the bacterium’s existing DNA. Transduction involves exchanging bacterial DNA through bacteriophages, or viruses that infect bacteria. If a bacteriophage attaches itself to a bacterium, its genome is inserted into the bacterium and its components are replicated in its host. The new bacteriophages then split open the bacterium, resulting in replicated viruses.

Antonie van Leeuwenhoek was a Dutch merchant and the very first to discover bacteria which he called “animalcules.” After building his own microscope, Leeuwenhoek scraped some plaque from his teeth and put it under the lens. Under the microscope, he could see the microscopic organisms that were living in his mouth. He sent a letter to the Royal Society of London detailing his findings. Leeuwenhoek’s letter remains the first record of bacteria living inside the human body. Bacteria have the same basic needs as many other organisms. They require food, which they break down in a process called respiration to make energy. Most bacteria require oxygen for this process. Since bacteria can thrive nearly everywhere, it is involved in many aspects of our daily world. Bacteria are used in environmental clean-up and recycling, and the production of food, fuel, and medications. The bacteria that grow in milk are essential for the creation of dairy products we eat every day, including yogurt, sour cream, and cheese. The human body has many helpful bacteria, and without them, you would become ill. These “good” bacteria help prevent harmful bacteria from growing and help digest food.

• Quiz Your Noodle: Bacteria

While less than 1 percent of bacteria cause disease, it’s important to protect yourself against “bad” germs to avoid getting sick. Various techniques can be used to stay disease-free, such as regular hand-washing, appropriate medications, and regular vaccinations. While hand-washing is often overlooked, it can be one of the most effective ways to protect yourself against bacteria and infections. Always wash your hands before preparing or eating food, after sneezing or coughing, and after using the toilet. Some medications will offer short-term protection from specific germs, such as an anti-parasitic medication if you are traveling to a foreign country. Being aware that not all bacteria are harmful, and understanding how to keep yourself protected from those that are, can help you stay healthy and strong.